Modern motor vehicles, in order to reduce tank leakage, that is to say an evaporation of fuel from a fuel tank of the motor vehicle, have reduction means in the form of filter devices which have activated carbon, so-called activated carbon filters. Owing to intensified demands with regard to consumption and emissions of motor vehicles, for example the change from LEVII to LEVIII in the USA, there is a need for a reduced purging quantity for the regeneration of activated carbon filters. A diffusion of hydrocarbons, also referred to as “bleeding emission”, is at the forefront of the reductions being sought.
A regeneration performance of the filter device in which the activated carbon is arranged horizontally, that is to say is loaded and purged horizontally, may possibly lead, in the case of small purging quantities of modern drive systems, to inadequate regeneration of the activated carbon, for example for so-called SHED tests. SHED tests are emissions tests in a gas-tight test chamber. An influence of the bleeding emissions on the regeneration of the activated carbon is evident here in particular.
The patent EP 1 446 569 B1 discloses a filter device for a motor vehicle, which filter device, for the reduction of fuel vapour emissions, has activated carbon as adsorption medium.
The U.S. Pat. No. 8,443,786 B2 discloses a filter device for a motor vehicle, the final chamber of which, with a connection to the atmosphere, has an activated carbon which differs from the other chambers. This likewise emerges from the laid-open specification US 2011/0315126 A1.
The laid-open specification DE 43 20 384 A1 has disclosed a filter device for a motor vehicle, the housing of which has at least two partitions which run between the atmosphere port and the tank port.
The U.S. Pat. No. 6,524,374 B2 describes a container in which fuel vapor flows through an inflow opening into the container, which has a chamber with adsorption medium through which the fuel vapor flows. Adsorbent holding filters, an adsorbent holding plate and an adsorbent holding spring are formed in the container.
The U.S. Pat. No. 8,529,676 B2 has disclosed a filter device for a motor vehicle, having a container, which has an adsorption medium, and having a flow regulating device close to an air connection port.